have been more than contented with one quarter of what you have said.
Exactly fifteen months ago, when I put pen to paper for this volume, I had
awful misgivings; and thought perhaps I had deluded myself, like so many
have done, and I then fixed in my mind three judges, on whose decision I
determined mentally to abide. The judges were Lyell, Hooker, and yourself.
It was this which made me so excessively anxious for your verdict. I am
now contented, and can sing my nunc dimittis. What a joke it would be if I
pat you on the back when you attack some immovable creationist! You have
most cleverly hit on one point, which has greatly troubled me; if, as I
must think, external conditions produce little DIRECT effect, what the
devil determines each particular variation? What makes a tuft of feathers
come on a cock's head, or moss on a moss-rose? I shall much like to talk
over this with you...

My dear Huxley, I thank you cordially for your letter.

Yours very sincerely,
C. DARWIN.

P.S.--Hereafter I shall be particularly curious to hear what you think of
my explanation of Embryological similarity. On classification I fear we
shall split. Did you perceive the argumentum ad hominem Huxley about
kangaroo and bear?


ERASMUS DARWIN (His brother.) TO CHARLES DARWIN.
November 23rd [1859].

Dear Charles,